Dental mandrel

ABSTRACT

A dental mandrel for placement and positioning of the female attachment portion of a dental bridgework or the like has a stem with depending tines to set within the attachment. The tines are provided with means whereby they spread outwardly to frictionally engage the attachment, and are also adapted for movement inwardly whereby the mandrel is easily engaged and disengaged from the attachment without disturbance of its position.

atent n 1 Poveromo Mar. 27, 1973 DENTAL MANDREL [76] Inventor: Melvin l). Poveromo, 1160 Kane Concourse, Suite 203, Miami Beach, Fla. 33154 [22] Filed: Apr. 20, 1972 [21] Appl. No.: 245,943

[52] US. Cl ..32/5 [51] Int. Cl ..A61c 13/22 [58] Field of Search ..32/5, 40, l

[56] References Cited UNITED STATES PATENTS 3,089,242 5/1963 Weissman ..32/5 3,535,787 10/1970 Korte ..'..32/5

Primary Examiner-Louis G. Mancene Assistant Examiner-.1. Q. Lever Attorney-Robert G. McMorrow [57] ABSTRACT A dental mandrel for placement and positioning of the female attachment portion of a dental bridgework or the like has a stem with depending tines to set within the attachment. The tines are provided with means whereby they spread outwardly to frictionally engage the attachment, and are also adapted for movement inwardly whereby the mandrel is easily engaged and disengaged from the attachment without disturbance of its position.

3 Claims, 5 Drawing Figures DENTAL MANDIREL BACKGROUND OF THE INVENTION bridgework to provide a female attachment in a dental 1 crown which is subsequently mated with an interfitting male connector in the final mounting of the bridge. It is further conventional practice to place the female attachment in the crown by means of a mandrel having an elongated stem and a depending single prong which fits into the cavity or mounting chamber of the female attachment. In such procedure, the prong must of necessity frictionally grip the attachment is order to perform the desired function.

SUMMARY OF THE INVENTION In the employment of female attachments of the type described above it is necessary in virtually all instances that a minimum of two such attachments be employed. Each female attachment in a particular installation must be precisely parallel. Mandrels of the single prong variety are presently supplied with the associated female attachment, but due to the diminutive dimensions involved, and the possibility of wear, temperature changes and the like, the maintenance of a snug connection is extremely difficult. The successful practice of the installation method however, requires careful and precise positioning of the female attachments. If a mandrel fits too closely in the attachment, its removal distorts the alignment of the attachment which is partially embedded in'a wax or a casting. In other instances, the prong is loose within the attachment, resulting in error in alignment. The present invention overcomes these difficulties by the provision of a mandrel having depending tines instead of a single prong, the tines including means for adjustment of their relative positions whereby they are moved to close proximate locations for placement and removal in the attachment, and thereafter spread apart for frictional engagement in the attachment during use.

In a first form of the invention, the means for adjustment of the tines comprises a threaded actuator, and in another form of the invention, the tines are inherently angled and are compressible toward one another for insertion and removal.

Other and further objects and advantages of the invention will become apparent to those skilled in the art from a consideration of the following specification when read in conjunction with the annexed drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 illustrates in perspective a first form of mandrel of this invention as employed in placement of a female attachment in a dental crown;

FIG. 2 is an enlarged side elevational view, partially broken away, of the mandrel and attachment;

FIG. 3 is a further enlarged detail cross section on line 33 of FIG. 2, looking in the direction of the arrows;

FIG. 4 is another sectional view on line 4-4 of FIG. 2, looking in the direction of the arrows; and

FIG. 5 shows a second form of the invention in side elevation.

DESCRIPTION OF THE PREFERRED EMBODIMENTS:

Referring initially to FIGS. 1 through 4, the first form of the invention is therein generally identified by reference character 10. The mandrel 10 in FIG. 1 is shown in use in the application of a female attachment 12 to be embedded in a crown 14 which may be either precast or of wax. Positioning of the female attachment in the crown is followed by stabilization of the position of the attachment using wax, solder, or other known procedures. Both this method and the female attachment are standard and not unique to the invention. For purposes of subsequent reference however, the attachment member includes a base 16 with an upstanding back wall 18 and curvilinear side walls 20, 22, projecting therefrom. The side walls have outward mounting flanges 24, 26, respectively, and a bottom flange 28 therewith defines a forwardly facing slot 30. The attachment is hollow, comprising a body portion with a chamber. The chamber receives subsequently a correspondingly shaped male connector (not shown, see for example, that type shown in US. Pat. No. 3,117,377).

A mandrel 10 is elongated and includes a cylindrical stem 32 having an upper end 34 and an opposite lower end 36. Integral with the lower end is an enlarged base 38 having a bottom wall 40.

The mandrel further includes a tine assembly 42 formed of metal such as steel, having the characteristic of a spring quality whereby upon deformation it tends to return to original configuration. The assembly 42 comprises a bifurcated prong 44 including-a first tine 46 and a second tine 48. The tines include facing proximal walls 50, 52, and opposite distal walls 54, 56, respectively. The distal walls are shaped to conform to the curvilinear surfaces of the attachment side walls 20 and 22.

The tine 48 has a threaded transverse bore 58 therein in which is mounted an expanding screw including an elongated, threaded screw member 60 having an inner contact end 62 and an outer handle or knob 64. Rotation of the handle or knob causes the screw to turn in the bore and to be advanced or retracted according to the direction of turning.

With the screw 60 retracted so that its end 62 is out of contact with the wall 50 of the tine 46, the tines assume a normal position wherein the distance between the distal walls 54 and 56 is less than the distance between the walls 20 and 22 and the prong assembly is therefore readily placed in or removed from the attachment without disturbance of its position. As the screw is turned inwardly, the end 62 contacts the wall 50 thereby spreading the tines, which causes tight frictional engagement between the walls 54, 56 and the attachment walls 22 and 20, respectively.

FIG. 5 shows a modification wherein a mandrel 10a has a stem 32a and base 38a. Extending from the bottom wall 40a of the base are tines 46a and 48a which are angled away from one another but are again formed of spring steel or material of like characteristics. Insertion in this instance is accomplished by compressing the tines toward one another, either with the fingers or with some appropriate force application device. When in place in the attachment, the compressing force is released which causes the tines to spring outwardly into attachment contact positions.

I claim: 1. An mandrel employed in a system of positioning of a female attachment in a dental procedure, the female attachment comprising a body portion having a chamber therein open at its top and having side walls, the mandrel comprising:

movable toward one another to discontinue the frictional contact and permit withdrawal from the female attachment.

2. The invention of claim 1, wherein:

said means for constantly urging the tines includes a transverse, internally threaded bore formed in one of said tines; and

an elongated screw operatively disposed in said bore for movement into contact with the other of said tines. 3. The invention of claim 1, wherein:

said means for constantly urging the tines comprises the tines being outwardly angled relative to one another and being adapted for temporary compression toward one another to diminish the lateral space occupied thereby. 

1. An mandrel employed in a system of positioning of a female attachment in a dental procedure, the female attachment comprising a body portion having a chamber therein open at its top and having side walls, the mandrel comprising: an elongated stem having an upper end and a lower end; an enlarged base at the lower end of the stem; a pair of depending tines extending from the base in substantially side-by-side relation to one another; and means for constantly urging the tines away from one another and into frictional engagement against the side walls of the female attachment, the tines being movable toward one another to discontinue the frictional contact and permit withdrawal from the female attachment.
 2. The invention of claim 1, wherein: said means for constantly urging the tines includes a transverse, internally threaded bore formed in one of said tines; and an elongated screw operatively disposed in said bore for movement into contact with the other of said tines.
 3. The invention of claim 1, wherein: said means for constantly urging the tines comprises the tines being outwardly angled relative to one another and being adapted for temporary compression toward one another to diminish the lateral space occupied thereby. 